Topological Defect-regulated Porous Carbon Anodes with fast Interfacial and Bulk Kinetics for High-rate and High-energy-density Potassium-ion Batteries

Carbonaceous materials are regarded as one of the most promising anodes for potassium-ion batteries (PIBs), but their rate capabilities have been largely limited by the slow solid-state potassium diffusion kinetics inside anode and sluggish interfacial potassium ion transfer process. Herein, high-rate and high-capacity PIBs have been demonstrated by facile topological defect-regulation of the microstructure of carbon anodes. The carbon lattice of the as-obtained porous carbon nanosheets with abundant topological defects (TDPCNSs) holds high potassium adsorption energy yet low potassium migration barrier, thereby enabling efficient storage and diffusion of potassium inside graphitic layers. Moreover, the topological defects can induce preferential decomposition of anions, leading to the formation of high potassium ion conductive solid electrolyte interphase (SEI) film with decreased potassium ion de-solvation and transfer barrier. Additionally, the dominant sp2-hybridized carbon conjugated skeleton of TDPCNSs enables high electrical conductivity (39.4 S cm-1) and relatively low potassium storage potential. As a result, the as-constructed TDPCNSs anode demonstrates high potassium storage capacity (504 mA h g-1 at 0.1 A g-1), remarkable rate capability (118 mA h g-1 at 40 A g-1) as well as long-term cycling stability. This article is protected by copyright. All rights reserved.

All-in-one porous membrane enables full protection in guided bone regeneration

The sophisticated hierarchical structure that precisely combines contradictory mechanical and biological characteristics is ideal for biomaterials, but it is challenging to achieve. Herein, we engineer a spatiotemporally hierarchical guided bone regeneration (GBR) membrane by rational bilayer integration of densely porous N-halamine functionalized bacterial cellulose nanonetwork facing the gingiva and loosely porous chitosan-hydroxyapatite composite micronetwork facing the alveolar bone. Our GBR membrane asymmetrically combine stiffness and flexibility, ingrowth barrier and ingrowth guiding, as well as anti-bacteria and cell-activation. The dense layer has a mechanically matched space maintenance capacity toward gingiva, continuously blocks fibroblasts, and prevents bacterial invasion with multiple mechanisms including release-killing, contact-killing, anti-adhesion, and nanopore-blocking; the loose layer is ultra-soft to conformally cover bone surfaces and defect cavity edges, enables ingrowth of osteogenesis-associated cells, and creates a favorable osteogenic microenvironment. As a result, our all-in-one porous membrane possesses full protective abilities in GBR.

Pseudocapacitive Potassium-Ion Intercalation Enabled by Topologically Defective Soft Carbon toward High-Rate, Large-Areal-Capacity, and Low-Temperature Potassium-Ion Batteries

Carbonaceous materials are widely investigated as anodes for potassium-ion batteries (PIBs). However, the inferior rate capability, low areal capacity, and limited working temperature caused by sluggish K-ions diffusion kinetics are still primary challenges for carbon-based anodes. Herein, a simple temperature-programmed co-pyrolysis strategy is proposed for the efficient synthesis of topologically defective soft carbon (TDSC) based on inexpensive pitch and melamine. The skeletons of TDSC are optimized with shortened graphite-like microcrystals, enlarged interlayer spacing, and abundant topological defects (e.g., pentagons, heptagons, and octagons), which endow TDSC with fast pseudocapacitive K-ion intercalation behavior. Meanwhile, micrometer-sized structure can reduce the electrolyte degradation over particle surface and avoid unnecessary voids, ensuring a high initial Coulombic efficiency as well as high energy density. These synergistic structural advantages contribute to excellent rate capability (116 mA h g-1 at 20 C), impressive areal capacity (1.83 mA h cm-2 with a mass loading of 8.32 mg cm-2 ), long-term cycling stability (capacity retention of 91.8% after 1200 h cycling), and low working temperature (-10 °C) of TDSC anodes, demonstrating great potential for the practical application of PIBs.

A Versatile Sulfur-Assisted Pyrolysis Strategy for High-Atom-Economy Upcycling of Waste Plastics into High-Value Carbon Materials

With the overconsumption of disposable plastics, there is a considerable emphasis on the recycling of waste plastics to relieve the environmental, economic, and health-related consequences. Here, a sulfur-assisted pyrolysis strategy is demonstrated for versatile upcycling of plastics into high-value carbons with an ultrahigh carbon-atom recovery (up to 85%). During the pyrolysis process, the inexpensive elemental sulfur molecules are covalently bonded with polymer chains, and then thermally stable intermediates are produced via dehydrogenation and crosslinking, thereby inhibiting the decomposition of plastics into volatile small hydrocarbons. In this manner, the carbon products obtained from real-world waste plastics exhibit sulfur-rich skeletons with an enlarged interlayer distance, and demonstrate superior sodium storage performance. It is believed that the present results offer a new solution to alleviate plastic pollution and reduce the carbon footprint of plastic industry.

Molecular Engineering toward High-Crystallinity Yet High-Surface-Area Porous Carbon Nanosheets for Enhanced Electrocatalytic Oxygen Reduction

Carbon-based nanomaterials have been regarded as promising non-noble metal catalysts for renewable energy conversion system (e.g., fuel cells and metal-air batteries). In general, graphitic skeleton and porous structure are both critical for the performances of carbon-based catalysts. However, the pursuit of high surface area while maintaining high graphitization degree remains an arduous challenge because of the trade-off relationship between these two key characteristics. Herein, a simple yet efficient approach is demonstrated to fabricate a class of 2D N-doped graphitized porous carbon nanosheets (GPCNSs) featuring both high crystallinity and high specific surface area by utilizing amine aromatic organoalkoxysilane as an all-in-one precursor and FeCl3 ·6H2 O as an active salt template. The highly porous structure of the as-obtained GPCNSs is mainly attributed to the alkoxysilane-derived SiOx nanodomains that function as micro/mesopore templates; meanwhile, the highly crystalline graphitic skeleton is synergistically contributed by the aromatic nucleus of the precursor and FeCl3 ·6H2 O. The unusual integration of graphitic skeleton with porous structure endows GPCNSs with superior catalytic activity and long-term stability when used as electrocatalysts for oxygen reduction reaction and Zn-air batteries. These findings will shed new light on the facile fabrication of highly porous carbon materials with desired graphitic structure for numerous applications.

P11.01 TMZ-LEV- IFN cocktail regimen significantly inhibited the growth of glioma

BACKGROUND

TMZ, is the first line chemotherapeutic drug for glioma, and drug resistance is one of the most important reasons for glioma treatment failure. Our previous studies have found that: 1) Type I interferon (IFN) could reverse the resistance of TMZ by inhibiting NF-κB activity, and down-regulating the expression of MGMT in vivo and in vitro; 2) IFN-α could significantly improve chemtherapeautic effect of TMZ for GBM patients. We aim to investigate the therapeutic effect of a cocktail chemotherapy regimen combining temozolomide (TMZ)- Levetiracetam(LEV) - interferon (IFN) on human glioma U138 and U251 subcutaneous xenograft tumor.

MATERIAL AND METHODS

30 xenograft tumors were established by subcutaneously injecting 1×106 glioma cells into the right flank of 4-week-old female BALB/C nude mice and then randomly divided into 5 groups (n=6/group): Control group; TMZ group; TMZ+IFN group; TMZ+LEV group; TMZ+LEV+IFN group. Anti-tumor efficacy of five regimens for tumor-bearing mice was tested after treatment with TMZ (50 mg/kg, i.p.), IFN (2×105 IU, s.c.), LEV (150 mg/kg, i.p.), while TMZ dose were reduced to 12.5 mg/kg for U251 tumors. All drugs are given once a day for five consecutive days. After therapy, the size of tumor was measured every day until the control tumors reached 2000 mm3. Mice bearing U138 tumors were sacrificed at 40 days after therapy, and mice bearing U251 tumors were killed at 26 days after therapy.

RESULTS

We identified that both U138 and U251 tumor growth among TMZ group, TMZ+IFN group, TMZ+LEV group and TMZ+LEV+IFN group were significantly inhibited (P<0.05), compared with the control group. Tumor weight of all treating group was lower than that of the control group (P<0.05). The tumor weight of TMZ+LEV+IFN group was the lowest and significantly lower than that of TMZ+LEV group and TMZ group (P<0.05, respectively). No significant difference was found between TMZ+LEV+IFN group and TMZ+IFN group in U251 subcutaneous xenograft tumors, although the tumor weight was lower in TMZ+LEV+IFN group (P>0.05). In the treatment of mice bearing U138 glioma, TMZ+LEV+IFN regimen was significantly superior to TMZ+IFN regimen.

CONCLUSION

Our data demonstrate that both IFN and LEV can sensitize TMZ effect on glioma. TMZ-LEV-IFN cocktail appears the best regimen.